We should think about what we can do ____________ (keep) animals and plants from becoming endangered.用所给动词的适当形式填空.答案是to keep,我想知道为什么加to啊?

分类: 作业答案 • 2022-02-17 16:25:26

问题描述：

We should think about what we can do ____________ (keep) animals and plants from becoming endangered.
用所给动词的适当形式填空.答案是to keep,我想知道为什么加to啊?

答